Antimicrobial and antiviral evaluation of compounds from Holoptelea integrifolia: in silico supported in vitro study

Holoptelea integrifolia, also known as the Indian Elm Tree, has been used in Ayurvedic medicine for its medicinal properties. In this study, two biologically active metabolites, 5(6) dihydrostigmast 22en 3-O-β-glucoside (DHS) and 1-O-eicosanoyl glycerol-2'-O-β-galactouronic (EGG), were isolated for the first time from the n-butanol fraction of H. integrifolia using a chromatographic technique and identified by NMR, and HRESI-MS. The antiviral and multidrug-resistant activities of these metabolites were evaluated as well as the n-butanol fraction. The n-butanol fraction of H. integrifolia exhibited weak antiviral effects, but DHS and EGG demonstrated significant antiviral activity against herpes simplex type-1 (HSV-1) and Coxsackie (CoxB4) viruses. Both metabolites showed lower IC50 values than the standard antiviral drug acyclovir, indicating their potency in inhibiting viral replication. EGG showed potent antiviral activity with minimal cytotoxicity at the highest concentration tested, presenting a selectivity index (SI) of 18.18 and 15.58 against HSV-1 and CoxB4 viruses, respectively. A preliminary assessment of the antibacterial activity of the n-butanol fraction and metabolites revealed that DHS had the highest inhibitory potency against drug-resistant strains, including MRSA and Carbapenem-resistant Klebsiella pneumonia. It also exhibited significant inhibitions against Fluconazole-resistant Candida albicans and ESBL - Escherichia coli. DHS displayed the lowest minimum inhibitory concentration (MIC) values, indicating its superiority as an antibacterial agent compared to EGG and the n-butanol fraction. Molecular docking analysis confirmed the antiviral and antibacterial actions of DHS and EGG by demonstrating their strong binding.

Design, synthesis, and anti-hepatocellular carcinoma of thiopyrimidine/chalcone hybrids as dual STAT3/STAT5 inhibitors

Among the promising therapeutic targets for treating cancer are the continuously active STAT proteins, which are important in the progression of many malignancies. Here, we detail the STAT3/5 inhibitory action and thiopyrimidine/chalcone hybrid design, production, and anti-hepatocellular carcinoma activity. The prepared hybrids were assessed for their cytotoxic effect on HepG2 and Huh7 liver cancer cells. The most active compounds 5e and 5h (IC50 range from 0.55 to 2.58 μM) were further evaluated against normal THLE cells to examine their safety profiles. The hybrids 5e and 5h were additionally tested for their potential to inhibit STAT3 and STAT5a. They showed dual inhibitory action, with a decrease in the level of STAT3 by 65 and 87 times, respectively, and a decrease in the level of STAT5 by 60 and 79.5 times, respectively, compared to the control. Additionally, western blot analysis of compound 5h revealed inhibition of STAT3 and STAT5 phosphorylation at Tyr705 and Tyr694, respectively, with only a slight decrease in the total expression of STAT3 and STAT5 proteins. And lastly, molecular docking research provided additional insight on the 5h binding mechanism in the STAT3 and STAT5 SH2 domains.

Drug Repurposing Approach in Developing New Furosemide Analogs as Antimicrobial Candidates and Anti-PBP: Design, Synthesis, and Molecular Docking

Multidrug-resistant microorganisms have become a global health problem, prompting research into new antimicrobials. Drug repurposing is a new technique in drug discovery used to improve drug development success. As a well-studied medication with a sulfonamide moiety, furosemide was chosen to study its antimicrobial effect on different microbial strains. In addition, a new family of furosemide analogs was investigated for their antimicrobial efficacy. According to the obtained results, the majority of the examined molecules exhibited potential antimicrobial activity. Compounds 3b and 4a had the best anti-MRSA results, with an MIC = 7.81 µg/mL. They also demonstrated potent anti-gram-negative activity against E. coli (MIC = 1.95 µg/mL and 3.91 µg/mL, respectively). A time-killing kinetics study against E. coli and MRSA showed bactericidal actions of 3b and 4a within 120-150 min. Moreover, an anti-PBP activity and an in vitro cytotoxicity evaluation were performed. Furosemide decreased the PBP2a levels in MRSA by 21.5% compared to the control. However, the furosemide analogs 3b and 4a demonstrated superior anti-PBP activity (55.9 and 57.1 % reduction in the expression of PBP2a, respectively). In addition, compound 4a was nearly nontoxic to normal WI-38 cells (IC₅₀ = 248.60 μg /mL) indicating its high safety profile. Finally, the ability of furosemide and compounds 3b and 4a to bind to the target PBP2a enzyme has also been supported by molecular docking research.

Design, synthesis, antimicrobial screening and molecular modeling of novel 6,7 dimethylquinoxalin-2(1H)-one and thiazole derivatives targeting DNA gyrase enzyme

New 6,7-dimethylquinoxalin-2(1H)-one and hydrazineylidene thiazol-4-one derivatives were synthesized, and evaluated for their in vitro antimicrobial activity. The obtained results revealed marked antimicrobial potential against four bacterial, and two fungal strains. Both 6,7-dimethyl-3-(2-(4-nitrophenyl)-2-oxoethyl)quinoxalin-2(1H)-one (4d), and 2-(2-(9H-fluoren-9-ylidene)hydrazineyl)-5-(2-(p-tolyl)hydrazineylidene)thiazol-4(5H)-one (11b) displayed significant antibacterial and antifungal activities having MIC ranges (1.98-15.6 mg/mL) and (1.98-3.9 mg/mL) compared to Tetracycline and Amphotericin B as standard drugs. In addition, they showed noticeable inhibitory activity against DNA gyrase enzyme. Interestingly the thiazole derivative (11b) showed marked inhibitory activity against DNA gyrase with IC₅₀ = 7.82 ± 0.45 μM better than that of ciprofloxacin. The time-kill kinetics profile of the most active compounds against S. aureus and E. coli microorganisms displayed both concentration dependent and time dependent reduction in the number of viable cells. Furthermore, molecular docking study of both compounds in the DNA gyrase binding site was performed, showing agreement with the in vitro inhibitory activities.

Thais savignyi tissue extract: bioactivity, chemical composition, and molecular docking

CONTEXT

Thais savignyi Deshayes (Muricidae) is widely distributed in the Red Sea. Its abundance and the history of Muricidae in traditional medicine make it a tempting target for investigation.

OBJECTIVE

To investigate the chemical profile and biological activities of T. savignyi tissue extracts.

MATERIALS AND METHODS

Methanol, ethanol, acetone, and ethyl acetate extracts from T. savignyi tissue were compared in their antioxidant by total antioxidant capacity, DPPH free radical scavenging, and total phenolic content. In addition, the antimicrobial, and antibiofilm properties (at 250 µg/mL) of the extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans. The antioxidant extract with greatest activity was assessed for cytotoxicity (range 0.4-100 µg/mL) against 3 human cancer cell lines (UO-31, A549 and A431), and its chemical composition was investigated using GC-MS. Moreover, docking simulation was performed to predict its constituents' binding modes/scores to the active sites of thymidylate kinase.

RESULTS

The ethyl acetate extract (Ts-EtOAc) showed the highest total antioxidant capacity (551.33 mg AAE/g dry weight), total phenolics (254.46 mg GAE/g dry weight), and DPPH scavenging (IC₅₀= 24.0 µg/mL). Ts-EtOAc exhibited strong antibacterial (MIC: 3.9 µg/mL against K. pneumoniae), antibiofilm (MIC: 7.81 µg/mL against S. aureus), and antifungal (MIC: 3.9 µg/mL against C. albicans) activities and considerable cytotoxicity against cancer cells (UO-31: IC₅₀= 19.96 ± 0.93, A549: IC₅₀= 25.04 ± 1.15 μg/mL). GC-MS identified multiple bioactive metabolites in Ts-EtOAc extract belonging to miscellaneous chemical classes. Molecular docking studies revealed that the constituents of Ts-EtOAc have antibacterial potential.

DISCUSSION AND CONCLUSIONS

T. savignyi extract has considerable antimicrobial and cytotoxic activities. Further studies are needed to isolate the active constituents of this snail for comprehensive drug discovery tests.

Design, synthesis, cytotoxicity, and molecular docking studies of novel thiazolyl-hydrazone derivatives as histone lysine acetyl-transferase inhibitors and apoptosis inducers

Compounds containing both thiazole and arylsulfone moieties are recognized for their high biological activity and ability to fight a variety of ailments. Thus, in this context, new derivatives of (thiazol-2-yl)hydrazone with an arylsulfone moiety were synthesized as CPTH2 analogs with potent anti-histone lysine acetyl-transferase activity. Compounds 3, 4, 10b, and 11b showed an excellent inhibitory effect on P300 (E1A-associated protein p300), compared to CPTH2. Among all the tested derivatives, compound 10b revealed the highest activity against both P300 and pCAF. In addition, the new hits were tested for anticancer efficacy against two leukemia cell lines. Most of them showed a moderate to potent antitumor effect on the k562 and CCRF-CEM cell lines. Interestingly, the activity of compound 10b against the k562 cell line was found to be higher than that of CPTH2. Furthermore, it showed a good safety profile, better than CPTH2 on normal cells. Molecular docking analysis was carried out to reveal the crucial binding contacts in the inhibition of the P300 and pCAF enzymes.

Pyrazoles and fused pyrimidines: Synthesis, structure elucidation, antitubercular activity and molecular docking study

BACKGROUND

Synthesis of new heterocyclic drugs in short reaction time with sufficient quantity is considered as a target for several pharmaceutical scientists. Thus, organic reactions proceeded on the surface of nano-sized catalysts to speed up the stimulation process.

OBJECTIVE

we aimed in this research to synthesize a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst to investigate their anti-tubercular activity.

METHODS

ZnO(NPs) was used in synthesis of novel series of thienylpyrazolopyrimidines bearing arylazo group by reaction of thiophene-enaminone and the amino-arylazopyrazoles in excellent yield. On the other hand, another series of theinyl-pyrazoles was synthesized through the reaction of the same enaminone with hydrazonoyl chlorides but the usage of ZnO(NPs) failed in such reactions.

RESULTS

The proposed structures of the products and the mechanistic pathways of the reactions were assured based on the spectral data and chemical evidences. Thienylpyrazole derivatives were assessed for their activity as Mycobacterium tuberculosis inhibitor and their results revealed that two thienylpyrazole derivatives 24d & 24f showed the most significant anti-mycobacterial activity with MIC values 0.70 & 1.29 µM/mL, respectively comparing with the MIC value = 0.60 µM/mL of the standard drug Rifampicin. Furthermore, the most active thienylpyrazole derivatives were investigated for their cytotoxic impact versus normal cells WI-38 (Normal human Lung fibroblast cells) using MTT assay. These thienylpyrazole derivatives exhibited good selective index profile. Moreover, 1,3,4-trisubstituted pyrazole analogues showed good interaction with the active site of enoyl-acyl carrier protein reductase (Mt InhA) through the molecular docking studies.

CONCLUSION

We succeeded to synthesis a new series of heterocyclic compounds carrying pyrazole moiety in the presence of ZnO nano-catalyst as anti-tubercular agents.

Dual EGFR/VEGFR2 inhibitors and apoptosis inducers: Synthesis and antitumor activity of novel pyrazoline derivatives

Novel derivatives of the pyrazoline scaffold were synthesized and investigated for their cytotoxicity against prostate (PC-3), hepatocellular (HepG2), and breast (MDA-MB-231) carcinoma cells. The most active compounds, 4a, 4b, 5b, and 7c, revealed significant and broad-spectrum anticancer activities with IC₅₀ values of 1.30-7.18 μM in comparison with doxorubicin (IC₅₀  = 5.12-7.33 μM). Additionally, they exhibited lower cytotoxicity against normal WI-38 cells, indicating their high safety profiles. Aiming to enlighten the inhibitory potential on receptor tyrosine kinases (RTKs), compounds 4a, 4b, 5b, and 7c were assessed for their activities against four different RTKs (EGFR, FGFR2, HER2, and VEGFR2) and their apoptotic potencies on PC-3 cells. The results revealed that compounds 5b and 7c are potent dual EGFR and VEGFR2 inhibitors (IC₅₀  = 0.21 and 0.23 μM, respectively, against EGFR; 0.22 and 0.21 μM, respectively, against VEGFR2), whereas they displayed moderate inhibitory activities against HER2 and FGFR2. Besides, compounds 4a, 4b, 5b, and 7c prompted apoptosis via the upregulation of Bax, p53, and caspase-3, together with the downregulation of the levels of Bcl-2. Also, it was found that compounds 5b and 7c are more potent as apoptosis inducers than the other tested derivatives. Furthermore, molecular docking analyses of compounds 4a, 4b, 5b, and 7c in the EGFR and VEGFR ATP binding sites were performed, to confirm the in vitro assays.

Synthesis of new arylazopyrazoles as apoptosis inducers: Candidates to inhibit proliferation of MCF-7 cells

New 4-arylazo-3,5-diamino-1H-pyrazole derivatives substituted in the 4-aryl ring with the acetyl moiety were designed and synthesized. The antiproliferative activity of the novel arylazopyrazoles was examined against the MCF-7 cell line. Among all target compounds, 8b (IC₅₀ 3.0 µM) and 8f (IC₅₀ 4.0 µM) displayed higher cytotoxicity as compared with the reference standard imatinib (IC₅₀ 7.0 µM). Further studies to explore the mechanism of action were performed on the most active hit of our library, 8b, via anti-CDK2 kinase activity. It demonstrated good inhibitory effects for CDK2 (IC₅₀ 0.24 µM) with 62.5% inhibition, compared with imatinib. The cell cycle analysis in the MCF-7 cell line revealed apoptosis induction by 8b and cell cycle arrest at the S phase. Docking in the CDK2 active site and pharmacophore modeling confirmed the affinity of 8b to the CDK2 active site. Absorption, distribution, metabolism, and excretion studies revealed that our target compounds are orally bioavailable, with no permeation through the blood-brain barrier.

Discovery of new non-acidic lonazolac analogues with COX-2 selectivity as potent anti-inflammatory agents

Herein, the design and synthesis of some novel 1,3,4-trisubstituted pyrazole derivatives was carried out through the structural modification of lonazolac. All the synthesized compounds were investigated for in vitro COX-1 & COX-2 inhibition and in vivo anti-inflammatory activity by a carrageenan rat paw edema model. Among them, the chalcones 2a and 2b were the most COX-2 selective derivatives (S.I. = 8.22 and 9.31, respectively) and revealed very good in vivo anti-inflammatory potency. Similarly, the compounds 4a, 6b, 7a and 8a exhibited good COX-2 selectivity and in vivo anti-inflammatory activity. The active compounds were selected to further investigate their ulcerogenic activity, and they were found to be less ulcerogenic (ulcer indices = 2.4-8.4) as compared to indomethacin (ulcer index = 17.6) and nearly as ulcerogenic as celecoxib (ulcer index = 8.1). Moreover, histological studies were performed to evaluate the safety of these compounds on the stomach, liver and kidney. Furthermore, a docking study was performed to determine possible binding of the most active compounds 2a and 2b, which showed high docking scores (-9.461 and -7.962 kcal mol^-1, respectively) that were comparable to that of celecoxib (-8.692 kcal mol^-1).